Logic for improved delta pressure based soot estimation on low restriction particulate filters

ABSTRACT

Vehicle exhaust system uses delta pressure based estimation of accumulated soot within a diesel particulate filter. The exhaust system has a diesel oxidation catalyst and a diesel particulate filter. A fuel injector is connected upstream from the diesel oxidation catalyst and the diesel particulate filter. A delta pressure sensor measures difference in pressure at inlet and outlet of the diesel particulate filter. A controller determines when to regenerate the diesel particulate filter based on an estimated amount of soot. The controller, in a first regeneration mode, causes the fuel injector to inject fuel at a first rate into the exhaust stream, and to re-evaluate amount of soot accumulated within the diesel particulate filter under increased volumetric flow. The controller, in a second regeneration mode, causes the fuel injector to inject fuel at a second rate into the exhaust stream in order to combust soot trapped in the diesel particulate filter.

BACKGROUND

This disclosure relates to an apparatus and method for controllingregeneration of a diesel particulate filter. Specifically, thisdisclosure relates to apparatus and method for validating sootestimation for determining when to regenerate a diesel particulatefilter.

RELATED ART

Vehicles, such as those equipped with diesel engines, may includeexhaust systems that have diesel particulate filters for removingparticulate matter from the exhaust stream. During use of the dieselparticulate filter, soot or other carbon-based particulate matteraccumulates on the filter. As particulate matter accumulates on thediesel particulate filter, restriction of the filter increases, causingbuildup of undesirable back pressure in the exhaust system. Increasedback pressure decreases engine efficiency and reduces engineperformance. Therefore, to prevent diesel particulate filters frombecoming excessively loaded with particulates, diesel particulatefilters are regularly regenerated by burning off (i.e., oxidizing) theparticulates that accumulate on the filters. Under most diesel engineoperating conditions, however, the engine exhaust temperature is too lowto cause the diesel particulate filter to completely regenerate withoutassistance. Thus, it is desirable to provide a means for assistingregeneration of the diesel particulate filter.

There are a number of known methods for regenerating diesel particulatefilters. One known method is to provide a diesel oxidation catalyst inthe exhaust system downstream of the engine exhaust outlet and prior tothe diesel particulate filter, and to operate the engine fuel injectionapparatus so as to inject a quantity of fuel late in the combustionstroke of the engine piston. This causes the unburned fuel to reach thediesel oxidation catalyst and be burned off in a catalyzed reactionusing the diesel oxidation catalyst so as to raise the exhausttemperature sufficiently to initiate regeneration of the dieselparticulate filter without substantially increasing the engine outputtorque. Similarly, fuel may be injected directly into the exhaust streamupstream of the diesel oxidation catalyst using a fuel delivery device.An example of such a system is disclosed in U.S. published applicationU.S. 2006/0101810, published May 18, 2006, which is herein incorporatedby reference in its entirety. Alternatively, it is known to heat adiesel particulate filter to a temperature sufficient to initiateregeneration using an electrical heating element.

Although these systems are generally effective for initiatingregeneration of a diesel particulate filter, each has certain drawbacksin application. One drawback is that regenerating the diesel particulatefilter is fuel and energy intensive, resulting in reduced overall fueland energy efficiency of the vehicle. Specifically, in a vehicle thatuses unburned fuel from either late fuel injection into the combustionstroke of the engine piston, or in a vehicle that injects fuel directlyinto the exhaust stream, excess fuel must be consumed in the dieselparticulate filter regeneration process. This manifests as decreasedoverall fuel economy, which is neither economically nor environmentallydesirable. Even in a vehicle that uses an electrical heating element toregenerate the diesel particulate filter, the electrical power necessaryto operate the heating element must be provided by the vehicle'selectrical system. Producing that extra electrical power requires thatthe vehicle engine provide additional power to the vehicle electricalgenerator, either as the electrical energy is being used, or to returnthe vehicle batteries to a full state of charge if the batteries areused to provide the necessary electrical energy. The additional powerprovided by the vehicle engine to the vehicle generator again manifestsas decreased overall fuel economy.

In order to reduce unnecessary or premature regeneration of the dieselparticulate filter, various methods and approaches are known fordetermining the level or amount of soot in a diesel particulate filter,and for determining the appropriate point in time to initiateregeneration of the diesel particulate filter. Since it takes excessfuel and energy consumption to actively regenerate a diesel particulatefilter, a system in which a diesel particulate filter regenerates toofrequently may result in unnecessary excess fuel and energy consumption,and therefore reduced fuel economy due to the excess fuel and energyused to burn off the soot from the diesel particulate filter.Conversely, a system in which the diesel particulate filter is notregenerated frequently enough may cause excess back pressure in theexhaust, which may also result in reduced fuel economy. Therefore, it isimportant to regenerate the diesel particulate filter only whennecessary to prevent excess back pressure in the exhaust throughout itsoperating range.

The use of low restriction diesel particulate filters makes it evenharder to accurately estimate the quantity of soot trapped by the dieselparticulate filter, especially during low exhaust flow operating cycles.The advantage of using low restriction diesel particulate filters, ofcourse, is that their reduced exhaust flow restriction facilitatesgreater overall efficiency and fuel mileage. This advantage is reducedwhen the diesel particulate filter is allowed to accumulate excessivesoot due to the reduced ability to estimate the amount of soot presentand to determine the appropriate point in time to initiate regenerationof the diesel particulate filter. Furthermore, a reduced ability toestimate the amount of soot present in the diesel particulate filter canlead to progressive failure of the diesel particulate filter, eitherduring ordinary operation or during the regeneration process.Specifically, diesel particulate filters may be designed to withstandordinary operation and normal regeneration events, whereas an overlyclogged diesel particulate filter may exceed the thermal tolerance ofthe diesel particulate filter during regeneration events.

Premature deterioration and/or failure of the diesel particulate filtermay result in the vehicle failing to meet emissions requirements, andmay result in increased warranty costs to original equipmentmanufacturers. While it is known to mitigate the possibility of suchdeterioration and/or failure of the diesel particulate filter by way ofhardware selection, in particular choosing a diesel particulate filterthat can withstand higher temperatures and temperature gradients, theuse of diesel particulate filters having such qualities adds significantcost to the vehicle.

Since improving fuel economy is desired, and in order to avoidunnecessary diesel particulate filter failures, there is a need for adiesel particulate filter regeneration method and apparatus which iscapable of better determining when to regenerate a diesel particulatefilter.

SUMMARY

According to one embodiment disclosed herein, a vehicle has an exhaustsystem implementing delta pressure based estimation of accumulated sootwithin a diesel particulate filter. An engine is connected to theexhaust system. The exhaust system has therein a diesel oxidationcatalyst and a diesel particulate filter. A fuel injector device isconnected to the exhaust system upstream from the diesel oxidationcatalyst and diesel particulate filter. A delta exhaust pressure sensorarrangement is configured to measure a difference in exhaust pressure atan inlet to the diesel particulate filter and at an outlet to the dieselparticulate filter. At least one controller is connected to the fuelinjector and to the delta exhaust pressure sensor arrangement. Thecontroller is configured to determine when to conduct an activeregeneration of the diesel particulate filter based on an estimatedamount of soot accumulated therein. The controller is further configuredto, in a first regeneration mode, cause the fuel injector device toinject fuel at a first rate into the exhaust stream, and to re-evaluatethe amount of soot accumulated within the diesel particulate filterunder increased volumetric flow of the exhaust stream. The controller isfurther configured to, in a second regeneration mode, cause the fuelinjector device to inject fuel at a second rate into the exhaust streamin order to combust soot trapped in the diesel particulate filter.

According to an embodiment disclosed herein, a method of estimating thesoot comprises connecting an exhaust pipe to an engine, the exhaust pipehaving therein a diesel oxidation catalyst and a diesel particulatefilter. A fuel injector device is connected to the exhaust pipe upstreamfrom the diesel oxidation catalyst and diesel particulate filter. Adelta exhaust pressure sensor arrangement is configured to measure adifference in exhaust pressure at an inlet to the diesel particulatefilter and at an outlet to the diesel particulate filter. At least onecontroller is connected to the fuel injector and to the delta exhaustpressure sensor arrangement. The at least one controller determines whento conduct an active regeneration of the diesel particulate filter basedon an estimated amount of soot accumulated therein. The at least onecontroller, in a first regeneration mode, causes the fuel injectordevice to inject fuel at a first rate into the exhaust stream, andre-evaluates soot accumulated within the diesel particulate filter underincreased volumetric flow of the exhaust stream. The at least onecontroller, in a second regeneration mode, causes the fuel injectordevice to inject fuel at a second rate, larger than the first rate, intothe exhaust stream in order to combust soot trapped in the dieselparticulate filter.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representation of an exhaust system implementing anembodiment of Logic for Improved Delta Pressure Based Soot Estimation inLow Restriction Particulate Filters according to the present disclosure,as described herein;

FIG. 2 is a graph of particulate filter delta exhaust pressure versusvolumetric exhaust flow rate for a clean diesel particulate filter andfor a soot loaded diesel particulate filter, as described herein;

FIG. 3A is a graph of diesel particulate filter temperature over timefor an exhaust system implementing a known soot estimation sequence, asdescribed herein; and

FIG. 3B is a graph of diesel particulate filter temperature over timefor an exhaust system implementing an embodiment of the Logic forImproved Delta Pressure Based Soot Estimation in Low RestrictionParticulate Filters according to the present disclosure, as describedherein.

DETAILED DESCRIPTION

Embodiments described herein relate to Logic for Improved Delta PressureBased Soot Estimation in Low Restriction Particulate Filters, and tomethods for use thereof. Embodiments of Logic for Improved DeltaPressure Based Soot Estimation in Low Restriction Particulate Filtersand method of use may be applied to various types of vehicles havingdiesel engines, including but not limited to passenger vehicles,recreational vehicles, commercial vehicles, such as highway orsemi-tractors with and without auxiliary power units (APUs), straighttrucks with and without APUs, buses, fire trucks, agricultural vehicles,construction vehicles, campers, motorhomes, rail travelling vehicles,and trailers with APUs or refrigeration units, for non-limiting example.It is further contemplated that embodiments described herein may beapplied to vehicles having hybrid electric drive including dieselengines.

In order to better determine when to conduct active regeneration of thediesel particulate filter by way of fuel injection into the exhaustflow, accurate estimation of the amount of accumulated soot within thediesel particulate filter is desired. However, vehicles having suchexhaust systems commonly operate for extended periods of time withinoperational regimes having generally low exhaust flow cycles, fornon-limiting example the operation of a truck driving through a city.This low exhaust flow causes soot estimation to occur at a lowvolumetric flow, which is when diesel particulate filter delta exhaustpressure sensor inaccuracy has the greatest impact on the overallaccuracy of estimation of the amount of accumulated soot within thediesel particulate filter.

Naturally, the Original Equipment Manufacturer (OEM) cannot control thevehicle drive cycle, which may under certain conditions only providereduced volumetric exhaust flow. The Logic for Improved Delta PressureBased Soot Estimation in Low Restriction Particulate Filters of thepresent disclosure solves this issue at least in part by providing anadditional process in which, before an active diesel particulate filterregeneration event is initiated, the engine and exhaust aftertreatmentsystem raises temperature of the exhaust passing through the dieselparticulate filter. Increasing the temperature of the exhaust passingthrough the diesel particulate filter lowers the density of the exhaustand thereby increases the volumetric exhaust flow. During thisadditional process, soot estimation is re-evaluated under increasedvolumetric flow of the exhaust in order to provide a reliable the sootestimation. Once re-evaluation of soot estimation is completed, theLogic for Improved Delta Pressure Based Soot Estimation in LowRestriction Particulate Filters of the present disclosure proceeds withan active regeneration.

More particularly, the Logic for Improved Delta Pressure Based SootEstimation in Low Restriction Particulate Filters of the presentdisclosure accomplishes increasing the temperature of the exhaustpassing through the diesel particulate filter, and subsequentlyregenerating the diesel particulate filter, without excessivelyincreasing NO₂ emissions.

The method and system of the present disclosure includes a fuel injectordevice, a diesel oxidation catalyst, and a diesel particulate filter.During a first regeneration mode of the regeneration process, the fuelinjection device injects fuel into the exhaust stream at a first rate.The injected fuel enters the diesel oxidation catalyst and favorablyoccupies catalytic reaction sites therein to reduce NO occupancy of thesame sites, and thereby reduce the amount of NO that is oxidized to NO₂,while increasing the exhaust temperature and volumetric flow.

At a determined time, such as when the exhaust backpressure becomesexcessive, or at a predetermined time interval, a second regenerationmode is initiated wherein fuel is injected at a second rate into theexhaust stream. During the second regeneration mode, the fuel that hasbeen injected into the exhaust stream oxidizes within the dieseloxidation catalyst. This raises the exhaust temperature sufficiently tocombust soot trapped on the diesel particulate filter. It is envisionedthat exhaust temperature enables combustion of substantially all soottrapped on the diesel particulate filter. In this way, the method andsystem of the present disclosure enables increasing exhaust temperatureand volumetric flow for the purpose of diesel particulate filter deltapressure soot estimation revalidation, and enables regeneration of thediesel particulate filter without substantially increasing NO₂emissions.

It is noted that the first rate at which the fuel injection deviceinjects fuel into the exhaust stream during the first regeneration modeof the regeneration process may be anywhere from five percent toninety-five percent of the second rate at which the fuel injectiondevice injects fuel into the exhaust stream during the secondregeneration mode of the regeneration process, provided that the firstrate at which the fuel injection device injects fuel into the exhauststream during the first regeneration mode of the regeneration process isnot sufficient to combust substantially all of the soot trapped on thediesel particulate filter.

Moreover, the Logic for Improved Delta Pressure Based Soot Estimation inLow Restriction Particulate Filters of the present disclosure determinesdiesel particulate filter delta pressure based soot estimation duringall modes of vehicle operation except during active particulate filterregeneration itself. The results of the diesel particulate filter deltapressure based soot estimation determined during ordinary modes ofvehicle operation, including those determined during operational regimeshaving generally low exhaust flow cycles, are then compared to thediesel particulate filter delta pressure based soot estimation performedduring increased volumetric exhaust flow. In this way, the Logic forImproved Delta Pressure Based Soot Estimation in Low RestrictionParticulate Filters of the present disclosure re-validates the sootestimation and further refines correlation between diesel particulatefilter delta pressure readings under various conditions, and actualaccumulation of soot within the diesel particulate filter.

The Logic for Improved Delta Pressure Based Soot Estimation in LowRestriction Particulate Filters of the present disclosure may beimplemented within a vehicle control unit or module, within an enginecontrol unit or module, and/or within an exhaust aftertreatment controlunit or module. The system and method of the present disclosure mayfurther use recursive machine learning, up to and including artificialintelligence and neural networking, in refining the correlation betweendiesel particulate filter delta pressure readings under variousconditions, diesel particulate filter delta pressure readings underincreased exhaust temperature and volumetric exhaust flow during thefirst regeneration mode, and actual accumulation of soot within thediesel particulate filter.

In order to facilitate this, the system and method of the presentdisclosure may further be provided with temperature sensors positionedsubsequent to the fuel injection device but prior to the dieseloxidation catalyst, subsequent to the diesel oxidation catalyst butprior to the diesel particulate filter, and subsequent to the dieselparticulate filter. In this way, the Logic for Improved Delta PressureBased Soot Estimation in Low Restriction Particulate Filters of thepresent disclosure is provided with temperature and volumetric exhaustflow data at each point in the system, and delta exhaust pressure acrossthe diesel particulate filter, under each of these operating conditions,including during the regeneration itself. The temperature sensorpositioned subsequent to the diesel particulate filter in particularprovides important information regarding the combustion of accumulatedsoot within the diesel particulate filter. This temperature informationis used by the Logic for Improved Delta Pressure Based Soot Estimationin Low Restriction Particulate Filters of the present disclosure tofurther validate and refine the estimation of soot accumulation withinthe diesel particulate filter.

Embodiments of the Logic for Improved Delta Pressure Based SootEstimation in Low Restriction Particulate Filters of the presentdisclosure and their method of use allow the OEM to use a lowerrestriction diesel particulate filter while improving soot estimationfor the purposes of determining when to regenerate the dieselparticulate filter in such a way as to reduce unnecessary dieselparticulate filter regeneration, despite operation of the vehicle inregimes having generally low exhaust flow cycles. This further resultsin the ability to operate vehicles with generally lower overall exhaustrestriction and improved energy efficiency and fuel economy. Moreover,the system and method of the present disclosure provides such apowertrain arrangement that provides improved fuel economy withoutresulting in vehicle repair and warranty issues.

Referring now to FIG. 1 , an embodiment of an exhaust system 10implementing the Logic for Improved Delta Pressure Based Soot Estimationin Low Restriction Particulate Filters of the present disclosure isshown. The exhaust system 10 includes an exhaust pipe 12 having exhaustflow 14 passing therethrough. The exhaust system 10 further includes adiesel oxidation catalyst 20 and a diesel particulate filter 30. Thediesel oxidation catalyst 20 functions to convert particulate matter,hydrocarbons, and carbon monoxide to carbon dioxide and water. Aselective catalytic reduction (SCR) system (not shown) that uses areagent such as ammonia to reduce NOx into nitrogen and water may bepresent. If an SCR system is present, ammonia is supplied to thecatalyst system by the injection of urea, sometimes referred to asDiesel Emissions Fluid (DEF), into the exhaust, which then undergoesthermal decomposition and hydrolysis into ammonia. Because diesel engineexhaust contains relatively high levels of particulate matter, catalyticconverters remove only 20-40% of particulate matter. The dieselparticulate filter 30 then functions to clean the remainder of theparticulates from the exhaust flow 14 prior to release into theatmosphere.

The exhaust system 10 implementing the Logic for Improved Delta PressureBased Soot Estimation in Low Restriction Particulate Filters of thepresent disclosure is further provided with a hydrocarbon (fuel)injector device 16 upstream of the diesel oxidation catalyst 20. A firstexhaust temperature sensor 18 is located at or near the inlet of thediesel oxidation catalyst 20. A second exhaust temperature sensor 22 islocated between the outlet of the diesel oxidation catalyst 20 and theinlet of the diesel particulate filter 30. A third exhaust temperaturesensor 32 is located at the outlet of the diesel particulate filter 30.A first exhaust pressure sensor 26 is located at the inlet of the dieselparticulate filter 30, and a second exhaust pressure sensor 28 islocated at the outlet of the diesel particulate filter 30. Together, thefirst exhaust pressure sensor 26 and the second exhaust pressure sensor28 function as a delta exhaust pressure sensor 24.

As discussed previously, before the Logic for Improved Delta PressureBased Soot Estimation in Low Restriction Particulate Filters of thepresent disclosure initiates an active diesel particulate filterregeneration event, the system and method raises the temperature of theexhaust flow 14 passing through diesel particulate filter 30. Duringthis first regeneration mode, the hydrocarbon (fuel) injector device 16injects fuel into the exhaust flow 14 at a relatively smaller rate. Thisincreases the temperature of the exhaust flow 14 passing through thediesel particulate filter 30, thereby increasing the volumetric exhaustflow. Ongoing estimation of the soot within the diesel particulatefilter 30 performed during ordinary modes of vehicle operation using thedelta exhaust pressure sensor arrangement 24 is then re-evaluated underincreased volumetric flow of the exhaust flow 14 through the dieselparticulate filter 30 in order to ensure the soot estimation isaccurate. Once re-evaluation of soot estimation within the dieselparticulate filter 30 is completed, the Logic for Improved DeltaPressure Based Soot Estimation in Low Restriction Particulate Filters ofthe present disclosure proceeds with an active regeneration of thediesel particulate filter 30 in a second regeneration mode. In this way,the Logic for Improved Delta Pressure Based Soot Estimation in LowRestriction Particulate Filters of the present disclosure furtherrefines the correlation between diesel particulate filter delta pressurereadings taken using the delta exhaust pressure sensor arrangement 24under various conditions, and actual accumulation of soot within thediesel particulate filter 30 as re-evaluated during the firstregeneration mode.

FIG. 2 illustrates how higher volumetric flow rate of the exhaustproduces higher accuracy pressure based soot estimation, due to sensorerror having a smaller relative impact. Specifically, FIG. 2 is a graphof volumetric flow rate lines for a clean diesel particulate filter andfor a dirty diesel particulate filter. The Y-axis is the particulatefilter delta exhaust pressure reading axis 50, and the X-axis is thevolumetric exhaust flow rate axis 52. A clean diesel particulate filterdelta exhaust pressure to volumetric flow rate line 54 is shown alongwith a soot loaded diesel particulate filter delta exhaust pressure tovolumetric flow rate line 56. The delta exhaust pressure sensorarrangement 24, like all sensors, has an accuracy range, represented atseveral points along the clean diesel particulate filter delta exhaustpressure to volumetric flow rate line 54 and along the soot loadeddiesel particulate filter delta exhaust pressure to volumetric flow rateline 56 as delta exhaust pressure sensor accuracy ranges 58. As can beseen at low volumetric exhaust flow rates, the significance of the deltaexhaust pressure sensor accuracy ranges 58 is much greater than at highvolumetric exhaust flow rates.

Referring now to FIGS. 3A and 3B, a known soot estimation sequence 74and a soot estimation sequence utilizing Logic for Improved DeltaPressure Based Soot Estimation in Low Restriction Particulate Filters 76are shown, respectively. Both graphs show a diesel particulate filtertemperature axis 70 and a time axis 72, and illustrate the events of thesoot estimation sequences 74 and 76. In both soot estimation sequences74 and 76, an initial period of normal operation 78 is followed by aregeneration trigger based upon soot estimation 80. In the known sootestimation sequence 74, the regeneration trigger based upon sootestimation 80 is followed directly by a period of active regeneration82. In the soot estimation sequence utilizing Logic for Improved DeltaPressure Based Soot Estimation in Low Restriction Particulate Filters76, the regeneration trigger based upon soot estimation 80 is followedby a first regeneration mode, being a period of increased exhausttemperature and volumetric exhaust flow 84.

Once increased exhaust temperature and volumetric exhaust flow isestablished, soot estimation validation at conditions for accuracy 86occurs. As discussed previously, ongoing estimation of the soot withinthe diesel particulate filter (not shown) performed during ordinarymodes of vehicle operation using the delta exhaust pressure sensorarrangement (not shown) is then re-evaluated under increased volumetricflow of the exhaust flow through the diesel particulate filter in orderto ensure the soot estimation is accurate. Once this is complete, asecond regeneration mode/period of active regeneration 88 occurs. Inboth of the known soot estimation sequence 74 and the soot estimationsequence utilizing Logic for Improved Delta Pressure Based SootEstimation in Low Restriction Particulate Filters 76, the period ofactive regeneration 82 and 88 is followed by a period of normaloperation 90.

While the Logic for Improved Delta Pressure Based Soot Estimation in LowRestriction Particulate Filters has been described with respect to atleast one embodiment, the arrangement and method can be further modifiedwithin the spirit and scope of this disclosure, as demonstratedpreviously. This application is therefore intended to cover anyvariations, uses, or adaptations of the system and method using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which the disclosure pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. A vehicle having an exhaust system implementingdelta pressure based estimation of accumulated soot within a dieselparticulate filter, comprising: an engine connected to an exhaustsystem, the exhaust system having therein a diesel oxidation catalystand a diesel particulate filter; a fuel injector device connected to theexhaust system upstream from the diesel oxidation catalyst and thediesel particulate filter; a delta exhaust pressure sensor arrangementconfigured to measure a difference in exhaust pressure at an inlet tothe diesel particulate filter and at an outlet to the diesel particulatefilter; and at least one controller connected to the fuel injector andto the delta exhaust pressure sensor arrangement, and being configuredto: 1.) determine when to conduct an active regeneration of the dieselparticulate filter based on an estimated amount of soot accumulatedtherein; 2.) in a first regeneration mode, cause the fuel injectordevice to inject fuel at a first rate into the exhaust stream, andre-evaluate amount of soot accumulated within the diesel particulatefilter under increased volumetric flow of the exhaust stream; and 3.) ina second regeneration mode, cause the fuel injector device to injectfuel at a second rate into the exhaust stream in order to combust soottrapped in the diesel particulate filter.
 2. The vehicle of claim 1,wherein: the at least one controller being further configured to atleast one of: re-evaluate the amount of soot accumulated within thediesel particulate filter during the first regeneration mode to ensurethe soot estimation is accurate; compare the re-evaluated amount of sootfrom the first regeneration mode with an initial estimated amount ofsoot; and further refine a correlation between diesel particulate filterdelta pressure readings under operating conditions, and actualaccumulation of soot as determined during the first regeneration mode.3. The vehicle of claim 2, wherein: the at least one controller beingconnected to at least one temperature sensor positioned at least one of:subsequent to the fuel injection device but prior to the dieseloxidation catalyst, subsequent to the diesel oxidation catalyst butprior to the diesel particulate filter, and subsequent to the dieselparticulate filter.
 4. The vehicle of claim 3, wherein: the at least onecontroller being further configured to, when in the first regenerationmode, cause the fuel injector device to inject fuel into the exhauststream at the first rate calculated to enter the diesel oxidationcatalyst and favorably occupy catalytic reaction sites therein to reduceNO occupancy of the same sites, and to reduce the amount of NO that isoxidized to NO₂, while increasing exhaust temperature and volumetricflow.
 5. The vehicle of claim 3, wherein: the first rate at which thefuel injection device injects fuel into the exhaust stream during thefirst regeneration mode being from five percent to ninety-five percentof the second rate at which the fuel injection device injects fuel intothe exhaust stream during the second regeneration mode, provided thatthe first rate is not sufficient to combust\the soot trapped on thediesel particulate filter.
 6. The vehicle of claim 3, wherein: the atleast one controller is at least one of: a vehicle control unit ormodule, an engine control unit or module, and an exhaust aftertreatmentcontrol unit or module.
 7. The vehicle of claim 3, wherein: the at leastone controller being further configured to use recursive machinelearning in refining the correlation between diesel particulate filterdelta pressure readings under operating conditions, under increasedexhaust temperature and volumetric exhaust flow during the firstregeneration mode, and actual accumulation of soot within the dieselparticulate filter.